5-carboxylic acid halide derivatives of 10, 11-dihydro-5h-dibenzo[a, d]cycloheptene



United States Patent C) 3,369,044 5- CARBOXYLIC ACID HALIDE DERIVA- TIVES OF 10,11 DIHYDRO 5H DI- BENZO[a,d]CYCLOI-IEPTENE Frederick Leonard, Rockville, Md., and Andr Gagneux,

Basel, Switzerland, assignors to Geigy Chemical Corporation, Greenburgh, N.Y., a corporation of Delaware N Drawing. Original application July 23, 1962, Ser. No. 211,847, now Patent No. 3,287,409, dated Nov. 22, 1966. Divided and this application Apr. 18, 1966, Ser. No. 543,023

2 Claims. (Cl. 260-544) H COX I wherein Y stands for the ethylene or vinylene group CH CH respectively and X represents hydroxy, halogen, particularly, chlorine and bromine, or amino.

It is to be understood that the alkali and alkaline earth metal salts of the carboxylic acid within the above formula, as well as any other obvious and equivalent salts thereof, are within the concept and scope of the instant invention.

The compounds of this invention may be conveniently synthesized in the following manner.

In a first step, 2-(phenylethyl)benzoic acid is prepared by hydrogenating benzylidene-phthalic anhydride, prepared from phthalic anhydride and phenylacetic acid; in a second step, the compound obtained is treated with polyphosphoric acid to effect cyclization to 10,11-dillydro-SH-dibenzo[a,d]cycloheptene-S-one; as a third step,

I 10,1l-dihydro-SH-dibenzo[a,d]cycloheptene is produced by refluxing the above ketone in lower alkanol in the presence of sodium; and in a further step refluxing the product of step four with butyl-lithiurn gives the desired 10,11 dihydro-SH-dibenzo[a,d]cycloheptene-S-carboxylic acid after addition of carbon dioxide.

To obtain a 5H-dibenzo[a,d]cycloheptene-S-carboxylic acid, the product of step three is halogenated and subsequently dehydrohalogenated to yield the SH-dibenzo [a,d]cycloheptene, which when treated with butyl-lithium and carbon dioxide, as described above, gives the desired carboxylic acid.

The corresponding S-carboxylic acid halides and 5- carboxamides are prepared in the ordinary manner by sequent treatment with a halide of a negative element, such as sulfur or phosphorus, and ammonia.

3,369,044 Taterite'd Feb. 13, 1968 ICE This synthesis may be graphically illustrated by the following equations:

H H H The symbol Y in the above formulae has the significance ascribed to it hereinabove and Z is halogen.

More specifically, the subject compounds may be made in accordance with the following more detailed process description.

(1) Benzylidene-phthalic anhydride prepared from phthalic anhydride and phenylacetic acid according to Org. Synth. Coll., vol. 2, J. Wiley, N.Y., 1943, p. 61, is hydrogenated in absolute dioxane in the presence of a Nickel-catalyst until the hydrogenation is completed and 2-phenylethyl benzoic acid is obtained.

(2) To this benzoic acid derivative percent polyphosphoric acid is added at about C. The reaction mixture is then stirred for about two hours. 10,11-dihydro-SH-dibenzo[a,d1-cycloheptene-5-one is obtained in consequence of this procedure.

(3) By adding sodium in absolute ethanol to this ketone under dry nitrogen with vigorous stirring, 10,11-dihydro- SH-dibenzo [a,d]cycloheptene is formed after refluxing for about /2 hour to about four hours and preferably for about one hour.

(4a) The desired carboxylic acid, 10,11-dihydro-5H- dibenzo[a,d]cycloheptene-S-carboxylic acid, is made by adding butyl-lithiurn in wax to a mechanically stirred solution of the reaction product of step three in absolute ether under dry oxygen-free nitrogen, refluxing the reaction mixture for about /2 hour to about four hours and then adding carbon dioxide to the reaction mixture.

(4b) The desired 5-H-dibenzo[a,d]cycloheptene-S-carboxylic acid is obtained, for example, by (1) brominating the product of step three by means of N-bromo-succinimide in the presence of benzoyl peroxide dissolved in carbon tetrachloride under reflux conditions, (2) dehydrobrominating the compound obtained by heating with pyridine and (3) treating the 5H-dibenzo{a,d]cycloheptene thus formed as described under 4a above.

(5) By treating the above carboxylic acids with, for example, thionyl halides or phosphorus halides, the corresponding S-carboxylic acid halide derivatives are obtained which can be converted to the S-carboxamide derivatives by treatment with ammonia.

The subject compounds are valuable and useful in further chemical synthesis. Particularly, they can be employed as starting materials in the synthesis of, for example, dialkylaminoalkyl 5H dibenzo[a,d]cycloheptene-5- carboxylates or N (dialkylaminoalkyl)-5H-dibenzo[a,d] cycloheptene 5 carboxamides and the corresponding 10,11-dihydro compounds.

Such compounds may be prepared readily by reacting the carboxylic acids or acid halides encompassed by Formula I with a dialkylamino alkanol or -alkyl halides. More specifically, the above 5-carboxylate derivatives are prepared by refluxing the carboxylic acids or acid chlorides with a dialkylamino alkyl halids or with a dialkylamino alkanol, respectively, and the above S-carboxamide derivatives are made by refluxing the carboxylic acid chlorides with an N,N-diall yl-alkylene-diamine.

Such derived compounds which may be represented by the following general formula:

H COABNR:

wherein A represents or NH B stands for lower alkylene R means lower alkyl Y is as defined hereinabove possess valuable pharmaceutical properties. More particularly, they exhibit anti-convulsant, spasmolytic and antiepileptic activity and can thus be used as anticonvulsant, spasmolytic and antiepi'leptic agents.

lMerely by illustration, fi-diethylaminoethyl 10,1l-dihydro-H-dibenzo[a,d]cycloheptene-S-carboxylate hydrochloride provides, for example, when administered to mice in doses of 100 mg./ kg. P.O., 100 percent protection against electroshock for more than 4 /2 hours and delays at the same dose the onset of convulsions and death brought about by metrazole.

However, compounds of Formula I wherein X denotes amino, i.e., S-carboxaunide derivatives, possess also utility per se as physiologically active agents. To illustrate, 10, 11 dihydro 5H dibenzo[a,dIcycloheptene-S-carboxamide, exhibits anti-convulsant, spasmolytic, and antiepileptic activity and it can thus be used as anti-convulsant, spasmolytic and anti-epileptic agent. This compound, for instance, when administered to mice in doses of 250 rug/kg. P.O., provided protection against electroshock for 6 hours.

Furthermore, the 5carboxylic acids comprised by Formula I are useful as rust or corrosion inhibitors.

These new compounds, the methods for their preparation and their use in further chemical synthesis may be exemplified more fully by the following illustrative examples. The temperatures therein are given in degrees centigrade.

EXAMPLE 1 10,1I-dihydro-SH-dibenzo[a,d]cycloheptene-S- carboxylic acid l) Z-(plzenylelhyl)-benz0ic acid.-Bcnzylidene-phthalic anhydride (33 g., 1.5 moles) prepared according to Org.

4 Synth. Coll., vol. 2, I. Wiley, N.Y., 1943, p. 61, was hydrogenated in 250-300 ml. of absolute dioxane, obtained peroxide-free by chromatography on basic aluminum oxide, in the presence of 60 g. Girdler stabilized Nickelcatalyst. The starting hydrogen pressure was 1700 psi. at 25 C., corresponding to 2880 psi. at 400 K. After shaking for three hours at the latter'temperature the pressure was 1330 p.s.i., corresponding to a hydrogen uptake of 92%. The crude, crystalline reaction mixture was Washed out with absolute dioxane, filtered through Celite and evaporated. Dissol-ving the resulting residue in 5 N ammonia-water, filtration and precipitation with cone. HCl at 0 under vigorous stirring resulted in 265 g., 78% slightly beige crystals, M.P. 118-125"; 1/(CCl C=O 1770 and 1690 cm.- Recrystallization from ether/pent-ane gave 249 g. 73%, pure phenylethyl benzoic acid; M.P. 128130, i/(CCl 0:0 1760 cm.- e(MOH) 2780 A., 1300, equivalent weight calc. 226, found 227.

(2) 10,11 dihydro 5H-dibenz0[a,d]cycl0heptene-5- 0ne.2-(phenylethyl)-benzoic acid (90.4 g., 0.4 moles) was added to 4 kg. of :polyphosphoric acid at After stirring at this temperature for 2 hours the reaction mixture was poured on 4 kg. ice with stirring and extracted with three 1 1. portions orf ether. The combined extracts were Washed twice with 500 m1. of 2 N Na CO thrice with 500 ml. of ice water, dried over MgSO and evaporated. Distillation of the brown residue yielded 70 g., 84%, of the desired ketone, B.P. 0.4 Torr 21 16330-16332; M.P. 32-33 (from MeOH at 0), 1/(liq.) C=O 1650 cm.- 6(MCOH) 2670 A., 16,000; e(CyClO- hex.) 2630 A., 18,000; e(isooctane) 2640 A., 16,600.

(3) 10,11 dihydro 5H-a'ibenzo[a,d]cycl0heptene.- Sodium (46.0 g., 2.00 moles) was added to 45.0 g. (0.216 mole) of the above ketone in 900 ml. absolute ethanol under dry nitrogen with vigorous stirring. After refluxing for 30 min. the reaction mixture was cooled, treated with 1 l. of icewater and extracted with two 2 1. of portions of ether. The organic phase was then washed twice with 1 1. water, dried over MgSO and evaporated. Crystallization of the residue from ethanol yielded 29.56 g., 70%, of the desired reaction product; M.P. 72-75.

(4) 10,11 dihydro SH-a'ibenzo[a,d]-cycl0heptene-5- carboxylz'c acid-Butyl-lithium (44.00 g., 0.137 mole, 20.0%) in wax was added to a magnetically stirred solution of 22.40 g. (0.115 mole) of the above cyclohe tene in 250 .ml. absolute ether under dry, oxygen-free (Fiesersolution) nitrogen. After heating to reflux for 1.5 hours the brown mixture was added to 300 g. finely crushed CO under vigorous stirring and simultaneous addition of 500 ml. of absolute ether. Stirring was continued on a waterbath for 30 min., after which all the CO had evaporated. Addition of 300 ml. 0.4 N Na CO solution was followed by washing with three 250 ml. portions of ether. Separation and acidification of the aqueous phase with ice cold 2 N HCl under 500 ml. ether, extraction with another 500 ml. of ether, drying of the organic phase over MgSO evaporation and recrystallization from CHCl pentane gave 17.95 g., 66%, of the desired car-boxylic acid; M.P. 215-218, vKBr C=O, 1690 cm.-

Analysis for C H O (NW 238.27): Calcd: C, 80.63; H, 5.92. Found: C,80.88; H, 6.23.

EXAMPLE 2 10,11-dihydro-5H-dibenzo-[a,d]cycloheptene-S- carboxylic acid chloride The carboxylic acid of Example 1 (2.38 g., 0.01 mole) was refluxed in 20 ml. of thionyl chloride with magnetic stirring under argon for one hour. After evaporation to dryness and recrystallization from pentane, 2.0 g. (78%) of the desired acid chloride was obtained; M.P. 64-65", 10:0, CHCI 1800, 1775 cmf CDCl 3.02 (8H), 5.08 (1H), 7.04 (4H).

5 EXAMPLE 3 10,11-dihydr-5H-dibenz0[a,d] cycloheptene-S- carboxamide 10,1l-dihydro-SH-dibenzo[a,d]cycloheptenecarboxylic acid (5 g.) were dissolved in 50 ml. of benzene and treated slowly with ml. of thionyl chloride. The mixture was refluxed for 18 hours and concentrated to a syrupy residue in vacuo, which was taken up in benzene and again concentrated to a syrup. The syrup was dissolved in 50 cc. of benzene, cooled to 5 and saturated with NH gas. The precipitate was filtered OE and washed well with water. After recrystallization from a mixture of water and alcohol, the desired product was obtained as white crystals. Yield 2 g.; M.P. 185-186".

Analysis for C H NO: Calcd: C, 80.98; H, 6.37; N, 5.90. Found: C, 80.90; H, 6.41; N, 5.92.

EXAMPLE 4 N-Z-(diethylamino ethyl) 10,11 dihydro-SH-dibenz [md] cycloheptene-5-carboxamide hydrochloride monohydrate 10,1l-dihydro-SH-dibenzoIa,d]cycloheptene S-carboxylic acid (9.2 g., 0.04 mole) was dissolved in 160 cc. of benzene and treated slowly with cc. of thionyl chloride. The mixture was refluxed for 18 hours and concentrated to a syrupy residue in vacuo, which was taken up in benzene and again concentrated to a syrup. The syrup was dissolved in 100 cc. of benzene and 4.7 g. (0.04 mole) of N,N-diethylethylenediamine in 500 cc. of benzene was added dropwise at room temperature. The reaction mixture was stirred and refluxed for 4 hours. Upon cooling crystals separated, which, after recrystallization from a mixture of isopropanol and ethanol 8:2, melted at 133- 135"; yield 6.7 g.

Analysis for C H ClN O Calcd: C, 67.76; H, 8.00; N, 7.16. Found: C, 67.79; H, 8.35; N, 7.00.

6 EXAMPLE 5 fl-Diethylaminoethyl 10,11 dihydro-5H-dibenz[a,d] cycloheptene-S-carboxylwte hydrochloride H COX wherein X represents chlorine or bromine.

2. A compound according to claim 1 wherein X is chlorine.

References Cited UNITED STATES PATENTS 3/1966 Davis et a1. 260-558 1/1966 Harms 260-570.8

OTHER REFERENCES C'ristol, J. Am. Chem. Soc., vol. 82, pp. 6155-6162, 1960, O.D. 1.A5.

LORRAINE A. WEINBERGER, Primary Examiner.

T. GALLOWAY, Assistant Examiner. 

1. A COMPOUND OF THE FORMULA 